From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751713AbaKJXzq (ORCPT ); Mon, 10 Nov 2014 18:55:46 -0500 Received: from mga14.intel.com ([192.55.52.115]:18761 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751313AbaKJXzo (ORCPT ); Mon, 10 Nov 2014 18:55:44 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="414540344" From: Andi Kleen To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Andi Kleen Subject: [PATCH 3/8] x86: Add intrinsics/macros for new rd/wr fs/gs base instructions Date: Mon, 10 Nov 2014 15:55:34 -0800 Message-Id: <1415663739-25525-3-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1415663739-25525-1-git-send-email-andi@firstfloor.org> References: <1415663739-25525-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen Add C intrinsics and assembler macros for the new rd/wr fs/gs base instructions and for swapgs. Very straight forward. Used in followon patch. For assembler only a few standard registers used by entry_64.S are defined. Signed-off-by: Andi Kleen --- arch/x86/include/asm/fsgs.h | 54 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 arch/x86/include/asm/fsgs.h diff --git a/arch/x86/include/asm/fsgs.h b/arch/x86/include/asm/fsgs.h new file mode 100644 index 0000000..1df5085 --- /dev/null +++ b/arch/x86/include/asm/fsgs.h @@ -0,0 +1,54 @@ +#ifndef _ASM_FSGS_H +#define _ASM_FSGS_H 1 + +#ifndef __ASSEMBLY__ + +static inline void swapgs(void) +{ + asm volatile("swapgs" ::: "memory"); +} + +/* Must be protected by X86_FEATURE_FSGSBASE check. */ + +static inline unsigned long rdgsbase(void) +{ + unsigned long gs; + asm volatile(".byte 0xf3,0x48,0x0f,0xae,0xc8 # rdgsbaseq %%rax" + : "=a" (gs) + :: "memory"); + return gs; +} + +static inline unsigned long rdfsbase(void) +{ + unsigned long fs; + asm volatile(".byte 0xf3,0x48,0x0f,0xae,0xc0 # rdfsbaseq %%rax" + : "=a" (fs) + :: "memory"); + return fs; +} + +static inline void wrgsbase(unsigned long gs) +{ + asm volatile(".byte 0xf3,0x48,0x0f,0xae,0xd8 # wrgsbaseq %%rax" + :: "a" (gs) + : "memory"); +} + +static inline void wrfsbase(unsigned long fs) +{ + asm volatile(".byte 0xf3,0x48,0x0f,0xae,0xd0 # wrfsbaseq %%rax" + :: "a" (fs) + : "memory"); +} + +#else + +/* Handle old assemblers. */ +#define RDGSBASE_R15 .byte 0xf3,0x49,0x0f,0xae,0xcf +#define WRGSBASE_RDI .byte 0xf3,0x48,0x0f,0xae,0xdf +#define WRGSBASE_R15 .byte 0xf3,0x49,0x0f,0xae,0xdf + +#endif /* __ASSEMBLY__ */ + +#endif -- 1.9.3